Polymer, a method of preparing the same, composite prepared from the polymer, and electrode and composite membrane each including the polymer or the composite

ABSTRACT

A polymer comprising a first repeating unit represented by Formula 1: 
                         
wherein R 1  to R 13  and Ar 1  in Formula 1 are defined in the specification.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean PatentApplication No. 10-2013-0003140, filed on Jan. 10, 2013, and all thebenefits accruing therefrom under 35 U.S.C. §119, the content of whichis incorporated herein in its entirety by reference.

BACKGROUND

1. Field

The present disclosure relates to a polymer, a method of preparing thesame, a composite prepared from the polymer, and an electrode and acomposite membrane, each including the polymer or the composite.

2. Description of the Related Art

According to the types of electrolyte and fuel used, fuel cells can beclassified as polymer electrolyte membrane fuel cells (“PEMFCs”), directmethanol fuel cells (“DMFCs”), phosphoric acid fuel cells (“PAFCs”),molten carbonate fuel cells (“MCFCs”), or solid oxide fuel cells(“SOFCs”).

PEMFCs operating at 100° C. or higher temperatures in non-humidifiedconditions, as compared to those operable at low temperatures, do notrequire a humidifier, and are known to be convenient in terms of controlof water supply and highly reliable in terms of system operation.Furthermore, such high-temperature PEMFCs may become more durableagainst carbon monoxide (CO) poisoning that may occur in fuelelectrodes. Thus, a simplified reformer may be used therefor. Due tothese advantages, PEMFCs operable at medium and high temperatures innon-humidified conditions are increasingly drawing attention.

Along with the current trends for increasing the operation temperatureof PEMPCs as described above, fuel cells operable at medium and hightemperatures are drawing more attention.

However, thermal stability, ionic conductivity, and mechanicalcharacteristics of the electrolyte membranes for fuel cells developed sofar are not satisfactory. Thus, there is a demand for electrolytemembranes having improved performance.

SUMMARY

Provided are a polymer, a method of preparing the same, a compositeprepared from the polymer, an electrode, and a composite membrane, eachincluding the polymer or the composite having improved performance.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect, a polymer includes a first repeating unitrepresented by Formula 1 below:

wherein, in Formula 1,

at least one of R₁ to R₁₃ is a proton-conducting group, and theremaining R₁ to R₁₃ are each independently selected from a hydrogenatom, a substituted or unsubstituted C1-C40 alkyl group, a substitutedor unsubstituted C1-C40 alkoxy group, a substituted or unsubstitutedC2-C40 alkenyl group, a substituted or unsubstituted C2-C40 alkynylgroup, a substituted or unsubstituted C6-C40 aryl group, a substitutedor unsubstituted C7-C40 arylalkyl group, a substituted or unsubstitutedC6-C40 aryloxy group, a substituted or unsubstituted C2-C40 heteroarylgroup, a substituted or unsubstituted C3-C40 heteroarylalkyl group, asubstituted or unsubstituted C2-C40 heteroaryloxy group, a substitutedor unsubstituted C4-C40 carbocyclic group, a substituted orunsubstituted C5-C40 carbocyclic alkyl group, a substituted orunsubstituted C4-C40 carbocyclic oxy group, a substituted orunsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group, and

Ar₁ is a substituted or unsubstituted C6-C40 arylene group, asubstituted or unsubstituted C7-C40 arylalkylene group, a substituted orunsubstituted C6-C40 arylene oxy group, a substituted or unsubstitutedC7-C40 arylalkylene oxy group, a substituted or unsubstituted C2-C40heteroarylene group, a substituted or unsubstituted C3-C40heteroarylalkylene group, a substituted or unsubstituted C2-C40heteroarylene oxy group, a substituted or unsubstituted C2-C40heteroarylalkylene oxy group, a substituted or unsubstituted C4-C40carbocyclic group, a substituted or unsubstituted C5-C40 carbocyclicalkylene group, a substituted or unsubstituted C4-C40 carbocyclic oxygroup, or a substituted or unsubstituted C4-C40 carbocyclic alkylene oxygroup.

According to another aspect, a composite membrane includes theabove-defined polymer.

According to another aspect, there is provided a composite, which is apolymerization product of a composition including the above-definedpolymer and at least one selected from compounds represented by Formulae14 to 19:

wherein, in Formula 14,

R₁, R₂, R₃, and R₄ are each independently a hydrogen atom, a substitutedor unsubstituted C1-C20 alkyl group, a substituted or unsubstitutedC1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenylgroup, a substituted or unsubstituted C2-C20 alkynyl group, asubstituted or unsubstituted C6-C20 aryl group, a substituted orunsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC2-C20 heteroaryl group, a substituted or unsubstituted C2-C20heteroaryloxy group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic oxy group, asubstituted or unsubstituted C2-C20 heterocyclic group, a halogen atom,a hydroxy group, or a cyano group; and

R₅ is a substituted or unsubstituted C1-C20 alkyl group, a substitutedor unsubstituted C1-C20 alkoxy group, a substituted or unsubstitutedC2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynylgroup, a substituted or unsubstituted C6-C20 aryl group, a substitutedor unsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC7-C20 arylalkyl group, a substituted or unsubstituted C2-C20 heteroarylgroup, a substituted or unsubstituted C2-C20 heteroaryloxy group, asubstituted or unsubstituted C2-C20 heteroarylalkyl group, a substitutedor unsubstituted C4-C20 carbocyclic group, a substituted orunsubstituted C4-C20 carbocyclic alkyl group, a substituted orunsubstituted C2-C20 heterocylic group, or a substituted orunsubstituted C2-C20 heterocyclic alkyl group,

wherein, in Formula 15,

R₅′ is a substituted or unsubstituted C1-C20 alkyl group, a substitutedor unsubstituted C1-C20 alkoxy group, a substituted or unsubstitutedC2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynylgroup, a substituted or unsubstituted C6-C20 aryl group, a substitutedor unsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC7-C20 arylalkyl group, a substituted or unsubstituted C2-C20 heteroarylgroup, a substituted or unsubstituted C2-C20 heteroaryloxy group, asubstituted or unsubstituted C2-C20 heteroarylalkyl group, a substitutedor unsubstituted C4-C20 carbocyclic group, a substituted orunsubstituted C4-C20 carbocyclic alkyl group, a substituted orunsubstituted C2-C20 heterocylic group, or a substituted orunsubstituted C2-C20 heterocyclic alkyl group; and

R₆ is selected from a substituted or unsubstituted C1-C20 alkylenegroup, a substituted or unsubstituted C2-C20 alkenylene group, asubstituted or unsubstituted C2-C20 alkynylene group, a substituted orunsubstituted C6-C20 arylene group, a substituted or unsubstitutedC2-C20 heteroarylene group, —C(═O)—, and —SO₂—,

wherein, in Formula 16,

A, B, C, D, and E are carbon atoms; or

one or two of A, B, C, D, and E are nitrogen atoms, and the remaining A,B, C, D, and E are carbon atoms,

R₇ and R₈ are linked to each other to form a ring, wherein the ring is aC6-C10 cycloalkyl group, a C3-C10 heteroaryl group, a fused C3-C10heteroaryl group, a C3-C10 heterocyclic group, or a fused C3-C10heterocyclic group,

wherein, in Formula 17,

A′ is a substituted or unsubstituted C1-C20 heterocyclic group, asubstituted or unsubstituted C4-C20 cycloalkyl group, or a substitutedor unsubstituted C1-C20 alkyl group; and

R₉ to R₁₆ are each independently a hydrogen atom, C1-C20 alkyl group, aC1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, aC1-C20 heteroaryl group, a C1-C20 heteroaryloxy group, a C4-C20cycloalkyl group, a C1-C20 heterocyclic group, a halogen atom, a cyanogroup, or a hydroxy group,

wherein, in Formula 18,

R₁₇ and R₁₈ are each independently a C1-C20 alkyl group, a C1-C20 alkoxygroup, a C6-C20 aryl group, a C6-C20 aryloxy group, or a grouprepresented by Formula 8A,

wherein, in Formulae 18 and 18a,

R₁₉ and R_(19′) are each independently a hydrogen atom, a C1-C20 alkylgroup, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxygroup, a halogenated C6-C20 aryl group, a halogenated C6-C20 aryloxygroup, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group, ahalogenated C1-C20 heteroaryl group, a halogenated C1-C20 heteroaryloxygroup, a C4-C20 cycloalkyl group, a halogenated C4-C20 cycloalkyl group,a C1-C20 heterocyclic group, or a halogenated C1-C20 heterocyclic group,

wherein, in Formula 19,

at least two groups selected from R₂₀, R₂₁, and R₂₂ are linked to eachother to form a group represented by Formula 19a,

the remaining R₂₀, R₂₁, and R₂₂ are each independently a hydrogen atom,a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, aC6-C20 aryloxy group, a halogenated C6-C20 aryl group, a halogenatedC6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxygroup, a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group,

at least two adjacent groups selected from R₂₃, R₂₄, and R₂₅ are linkedto each other to form a group represented by Formula 19a, and

the remaining R₂₃, R₂₄, and R₂₅ are each independently a C1-C20 alkylgroup, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxygroup, a halogenated C6-C20 aryl group, a halogenated C6-C20 aryloxygroup, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group, ahalogenated C1-C20 heteroaryl group, a halogenated C1-C20 heteroaryloxygroup, a C4-C20 carbocyclic group, a halogenated C4-C20 carbocyclicgroup, a C1-C20 heterocyclic group, or a halogenated C1-C20 heterocyclicgroup,

wherein, in Formula 19a,

R₁′ is a substituted or unsubstituted C1-C20 alkyl group, a substitutedor unsubstituted C1-C20 alkoxy group, a substituted or unsubstitutedC2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynylgroup, a substituted or unsubstituted C6-C20 aryl group, a substitutedor unsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC7-C20 arylalkyl group, a substituted or unsubstituted C2-C20 heteroarylgroup, a substituted or unsubstituted C2-C20 heteroaryloxy group, asubstituted or unsubstituted C2-C20 heteroarylalkyl group, a substitutedor unsubstituted C4-C20 carbocyclic group, a substituted orunsubstituted C4-C20 carbocyclic alkyl group, a substituted orunsubstituted C2-C20 heterocylic group, or a substituted orunsubstituted C2-C20 heterocyclic alkyl group, and

* indicates a binding site to at least two adjacent groups of R₂₀, R₂₁,and R₂₂ in Formula 19, and a binding site to at least two adjacentgroups of R₂₃, R₂₄, and R₂₅ in Formula 19.

According to another aspect, an electrode includes the above-definedpolymer or the above-defined composite.

According to another aspect, a composite membrane includes theabove-defined polymer or the above-defined composite.

According to another aspect, a method of preparing the above-definedpolymer comprises:

reacting a compound represented by Formula 9 and a compound representedby Formula 10 to prepare the above-defined polymer:

wherein in Formula 9,

at least one of R₁ to R₁₃ is a proton-conducting group, and

the remaining R₁ to R₁₃ are each independently selected from a hydrogenatom, a substituted or unsubstituted C1-C40 alkyl group, a substitutedor unsubstituted C1-C40 alkoxy group, a substituted or unsubstitutedC2-C40 alkenyl group, a substituted or unsubstituted C2-C40 alkynylgroup, a substituted or unsubstituted C6-C40 aryl group, a substitutedor unsubstituted C7-C40 arylalkyl group, a substituted or unsubstitutedC6-C40 aryloxy group, a substituted or unsubstituted C2-C40 heteroarylgroup, a substituted or unsubstituted C3-C40 heteroarylalkyl group, asubstituted or unsubstituted C2-C40 heteroaryloxy group, a substitutedor unsubstituted C4-C40 carbocyclic group, a substituted orunsubstituted C5-C40 carbocyclic alkyl group, a substituted orunsubstituted C4-C40 carbocyclic oxy group, a substituted orunsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group; and Y is a halogen atom,OH—Ar₁—OH  Formula 10wherein, in Formula 10,

Ar₁ is a substituted or unsubstituted C6-C40 arylene group, asubstituted or unsubstituted C7-C40 arylalkylene group, a substituted orunsubstituted C6-C40 arylene oxy group, a substituted or unsubstitutedC7-C40 arylalkylene oxy group, a substituted or unsubstituted C2-C40heteroarylene group, a substituted or unsubstituted C3-C40heteroarylalkylene group, a substituted or unsubstituted C2-C40heteroarylene oxy group, a substituted or unsubstituted C2-C40heteroarylalkylene oxy group, a substituted or unsubstituted C4-C40carbocyclic group, a substituted or unsubstituted C5-C40 carbocyclicalkylene group, a substituted or unsubstituted C4-C40 carbocyclic oxygroup, or a substituted or unsubstituted C4-C40 carbocyclic alkylene oxygroup.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings of which:

FIG. 1 is a perspective exploded view of a fuel cell according to anembodiment;

FIG. 2 is a cross-sectional diagram of a membrane-electrode assembly(“MEA”) of the fuel cell of FIG. 1;

FIG. 3 is a graph of weight loss (percent, %) versus temperature (degreeCentigrade, ° C.) illustrating results of thermogravimetric analysis(“TGA”) on electrolyte membranes of Examples 4 to 6 and ComparativeExample 1;

FIG. 4 is a graph of conductivity (millisiemens per centimeter, mS/cm)versus relative humidity (percent of relative humidity, % RH) in theelectrolyte membranes of Example 6 and Comparative Example 1; and

FIGS. 5 to 12 are graphs of intensity (arbitrary units, a.u.) versuschemical shift (parts per million, ppm) representing proton nuclearmagnetic resonance spectra (“¹H-NMR”) of polymers of PreparationExamples 1 to 8.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments a polymer, a methodof preparing the same, a composite prepared from the polymer, anelectrode and a composite membrane each including the composite, and afuel cell including at least selected from the electrode and thecomposite membrane, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to the likeelements throughout. In this regard, the present embodiments may havedifferent forms and should not be construed as being limited to thedescriptions set forth herein. Accordingly, the embodiments are merelydescribed below, by referring to the figures, to explain aspects of thepresent description. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list.

It will be understood that when an element is referred to as being “on”another element, it can be directly in contact with the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

According to an embodiment, there is provided a polymer including afirst repeating unit represented by Formula 1 below:

In Formula 1,

at least one of R₁ to R₁₃ is a proton-conducting group, and theremaining R₁ to R₁₃ are each independently selected from a hydrogenatom, a substituted or unsubstituted C1-C40 alkyl group, a substitutedor unsubstituted C1-C40 alkoxy group, a substituted or unsubstitutedC2-C40 alkenyl group, a substituted or unsubstituted C2-C40 alkynylgroup, a substituted or unsubstituted C6-C40 aryl group, a substitutedor unsubstituted C7-C40 arylalkyl group, a substituted or unsubstitutedC6-C40 aryloxy group, a substituted or unsubstituted C2-C40 heteroarylgroup, a substituted or unsubstituted C3-C40 heteroarylalkyl group, asubstituted or unsubstituted C2-C40 heteroaryloxy group, a substitutedor unsubstituted C4-C40 carbocyclic group, a substituted orunsubstituted C5-C40 carbocyclic alkyl group, a substituted orunsubstituted C4-C40 carbocyclic oxy group, a substituted orunsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group, and

Ar₁ is a substituted or unsubstituted C6-C40 arylene group, asubstituted or unsubstituted C7-C40 arylalkylene group, a substituted orunsubstituted C6-C40 arylene oxy group, a substituted or unsubstitutedC7-C40 arylalkylene oxy group, a substituted or unsubstituted C2-C40heteroarylene group, a substituted or unsubstituted C3-C40heteroarylalkylene group, a substituted or unsubstituted C2-C40heteroarylene oxy group, a substituted or unsubstituted C2-C40heteroarylalkylene oxy group, a substituted or unsubstituted C4-C40carbocyclic group, a substituted or unsubstituted C5-C40 carbocyclicalkylene group, a substituted or unsubstituted C4-C40 carbocyclic oxygroup, or a substituted or unsubstituted C4-C40 carbocyclic alkylene oxygroup.

The proton-conducting group may be any of various groups known in theart to provide proton conductivity. For example, the proton-conductinggroup may be at least one of —SO₂H, —CO₂H, or —PO₃H.

In some embodiments, at least three of R₁ to R₁₂ in Formula 1 may beproton-conducting groups. For example, at least one of R₁ to R₄, atleast one of R₅ to R₉, and at least one of R₁₀ to R₁₂ may beproton-conducting groups to provide a polymer having higherconductivity.

In some embodiments, R₂, R₈, and R₁₁ in Formula 1 may all beproton-conducting groups, and the remaining R₁ to R₁₃ in Formula 1 mayall be hydrogen atoms.

In Formula 1, Ar₁ is an arylene group or an arylene group including ahetero atom,

The terms “arylene group including a hetero atom” indicates a divalentorganic group with a linker including a hetero atom between two arylenegroups, or an arylene group substituted with a substituent including ahetero atom between two arylene groups. In this regard, the hetero atomindicates at least one selected from sulfur, oxygen, nitrogen, fluorine,and chloride.

For example, the arylene group including a hetero atom, i.e., Ar₁ inFormula 1, may be a unit represented by Structural Formula 1 below:

In Formula 1,

X may be —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—,—S(═O)₂—, —CH(CCl₃)—, or a group represented by Structural Formula 1abelow:

In Structural Formula 1a,

R′ is a hydrogen atom, a C1-C40 alkyl group, a C1-C40 alkoxy group, aC2-C40 alkenyl group, a C2-C40 alkynyl group, a C6-C40 aryl group, aC7-C40 arylalkyl group, a C6-C40 aryloxy group, a C2-C40 heteroarylgroup, a hydroxy group, a cyano group, or a halogen atom.

According to an embodiment, the polymer includes a repeating unitincluding an organic phosphine oxide (P(═O)R₃, wherein R is an alkylgroup or an aryl group) moiety including an alkyl or aryl group. Such apolymer has increased thermal stability. The first repeating unitrepresented by Formula 1 above includes a proton-conducting groupexhibiting high proton conductivity. The first repeating unit mayinclude at least one proton-conducting group, for example, at leastthree proton conducting groups.

In some embodiments, Ar₁ may be a unit represented by Structural Formula1b below:

In some other embodiments, the polymer may further include a secondrepeating unit represented by Formula 2 below.

The first repeating unit and the second repeating unit may each have amole fraction from about 0.01 to about 0.99, and a sum of the molefractions of the first repeating unit and the second repeating unit maybe equal to 1:

In Formula 2,

A and Ar₂ may be each independently a substituted or unsubstitutedC6-C40 arylene group, a substituted or unsubstituted C7-C40 arylalkylenegroup, a substituted or unsubstituted C6-C40 arylene oxy group, asubstituted or unsubstituted C7-C40 arylalkylene oxy group, asubstituted or unsubstituted C2-C40 heteroarylene group, a substitutedor unsubstituted C3-C40 heteroarylalkylene group, a substituted orunsubstituted C2-C40 heteroarylene oxy group, a substituted orunsubstituted C2-C40 heteroarylalkylene oxy group, a substituted orunsubstituted C4-C40 carbocyclic group, a substituted or unsubstitutedC5-C40 carbocyclic alkylene group, a substituted or unsubstituted C4-C40carbocyclic oxy group, or a substituted or unsubstituted C4-C40carbocyclic alkylene oxy group.

In Formula 2,

A and Ar₂ may be each independently an arylene group, or an arylenegroup including a hetero atom.

In Formula 2,

A and Ar₂ may each independently be a unit represented by StructuralFormula 2 below:

In Structural Formula 2, X may be —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—.

In some embodiments, Ar₂ in Formula 2 may be a unit represented byStructural Formula 1 b below:

In other embodiments, A in Formula 2 may be a unit represented byFormula Structural 2a below:

A polymer represented by Formula 2 may be prepared by reacting acompound of Formula 10 below, wherein Ar₁ is Ar₂ with a compound ofFormula 11 below.

In some embodiments, the polymer may have a weight average molecularweight from about 5,000 to about 950,000. When the weight averagemolecular weight of the polymer is within this range, it may be easierto form a composite membrane due to improved processability withoutreduction in its thermal stability and mechanical characteristics.

In some embodiments, the polymer may be represented by Formula 3a,Formula 4a, or Formula 5a below:

In Formula 3a,

X may be a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—X;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 4a,

X may be a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅— or —CH(CCl₃)—;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 5a,

X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—, —CH(CF₃)—,—S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In some other embodiments, the polymer may be a polymer represented byFormula 3, Formula 4, or Formula 5 below:

In Formula 3,

X may be a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 4,

X may be a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 5,

X may be a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—, —C(CCl₃)₂—,—CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In still other embodiments, the polymer may be represented by Formulae6, 7, 7a, or 8 below.

In Formula 6,

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 7,

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 7a,

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In Formula 8,

0.01≦a≦0.99; and

0.01≦b≦0.99,

wherein a+b=1; and

n, which is a degree of polymerization, is ranging from about 5 to about5,000.

In some embodiments, a and b may each independently be from about 0.1 toabout 0.9. For example, a may be from about 0.1 to about 0.5, and b maybe from about 0.5 to about 0.9.

According to another embodiment, a method of preparing a polymerincluding a first repeating unit of Formula 1 above includes reacting acompound represented by Formula 9 below and a compound represented byFormula 10 below.

In Formula 9,

at least one of R₁ to R₁₃ is a proton-conducting group, and

the remaining R₁ to R₁₃ are each independently selected from a hydrogenatom, a substituted or unsubstituted C1-C40 alkyl group, a substitutedor unsubstituted C1-C40 alkoxy group, a substituted or unsubstitutedC2-C40 alkenyl group, a substituted or unsubstituted C2-C40 alkynylgroup, a substituted or unsubstituted C6-C40 aryl group, a substitutedor unsubstituted C7-C40 arylalkyl group, a substituted or unsubstitutedC6-C40 aryloxy group, a substituted or unsubstituted C2-C40 heteroarylgroup, a substituted or unsubstituted C3-C40 heteroarylalkyl group, asubstituted or unsubstituted C2-C40 heteroaryloxy group, a substitutedor unsubstituted C4-C40 carbocyclic group, a substituted orunsubstituted C5-C40 carbocyclic alkyl group, a substituted orunsubstituted C4-C40 carbocyclic oxy group, a substituted orunsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group; and Y is a halogen atom.OH—Ar₁—OH  Formula 10

In Formula 10,

Ar₁ is a substituted or unsubstituted C6-C40 arylene group, asubstituted or unsubstituted C7-C40 arylalkylene group, a substituted orunsubstituted C6-C40 arylene oxy group, a substituted or unsubstitutedC7-C40 arylalkylene oxy group, a substituted or unsubstituted C2-C40heteroarylene group, a substituted or unsubstituted C3-C40heteroarylalkylene group, a substituted or unsubstituted C2-C40heteroarylene oxy group, a substituted or unsubstituted C2-C40heteroarylalkylene oxy group, a substituted or unsubstituted C4-C40carbocyclic group, a substituted or unsubstituted C5-C40 carbocyclicalkylene group, a substituted or unsubstituted C4-C40 carbocyclic oxygroup, or a substituted or unsubstituted C4-C40 carbocyclic alkylene oxygroup.

The reacting of the compound of Formula 9 and the compound of Formula 10may include an azeotropic distillation by primarily thermal-treating thecompound of Formula 9 and the compound of Formula 10 with an addition ofa base and a solvent at a temperature of about 110° C. to about 165° C.

The base may be potassium carbonate, sodium carbonate, or the like. Thebase may neutralize and remove an acid component resulting from thereaction.

An amount of the base may be from about 2 moles to about 2.1 moles basedon 1 mole of the compound of Formula 10. When the amount of the base iswithin this range, the acid component as a reaction product may beeffectively removed to obtain the polymer with a higher yield.

The solvent may be any solvent able to dissolve the compound of Formula9 and the compound of Formula 10. Non-limiting examples of the solventare dichloromethane, chloroform, benzene, toluene, chlorobenzene, methylacetate, ethyl acetate, γ-butyrolactone, acetone, methyl ethyl ketone,cyclohexanone, ether, 1,2-dimethoxyethane (“DME”), 1,2-diethoxyethane,tetrahydrofuran (“THF”), 1,4-dioxane, a chain-type carbonate (such asdimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, anddipropyl carbonate), a cyclic carbonate (such as ethylene carbonate,propylene carbonate, and butylene carbonate), methanol, ethanol, water,dimethylsulfoxide (“DMSO”), N-methyl-2-pyrrolidone (“NMP”),N,N-dimethylformamide (“DMF”), and N, N-dimethyl acetamide (“DMA”). Acombination comprising at least one of the foregoing solvents can beused. Any suitable solvent available for these purposes in the art maybe used.

The method may include secondarily thermal-treating a reaction productfrom the primary thermal-treating at a temperature of about 120° C. toabout 190° C.

An amount of the compound of Formula 10 may be from about 1 mole toabout 1.1 mole based on 1 mole of the compound of Formula 9.

In some embodiments, a compound of Formula 11 below may be further addedin the reacting of the compound of Formula 9 and the compound of Formula10. In this regards, an amount of the compound of Formula 11 may varydepending on a mole fraction of the second repeating unit of Formula 2.Y-A-Y  Formula 11

In Formula 11,

A may be a substituted or unsubstituted C6-C40 arylene group, asubstituted or unsubstituted C7-C40 arylalkylene group, a substituted orunsubstituted C6-C40 arylene oxy group, a substituted or unsubstitutedC7-C40 arylalkylene oxy group, a substituted or unsubstituted C2-C40heteroarylene group, a substituted or unsubstituted C3-C40heteroarylalkylene group, a substituted or unsubstituted C2-C40heteroarylene oxy group, a substituted or unsubstituted C2-C40heteroarylalkylene oxy group, a substituted or unsubstituted C4-C40carbocyclic group, a substituted or unsubstituted C5-C40 carbocyclicalkylene group, a substituted or unsubstituted C4-C40 carbocyclic oxygroup, or a substituted or unsubstituted C4-C40 carbocyclic alkylene oxygroup; and Y may be a halogen atom.

As described above, when the compound of Formula 11 is added, a polymerincluding a first repeating unit of Formula 1 and a second repeatingunit of Formula 2 may be obtained. In this case, the polymer representedby Formula 2 may be prepared by reacting a compound of Formula 10,wherein Ar1 is Ar2, with a compound of Formula 11.

Non-limiting examples of the compound of Formula 9 arebis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide, and(bis(4-chloro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide.

Non-limiting examples of the compound of Formula 10 are4,4′-dihydroxybiphenyl(p,p′-biphenol), or a compound represented byFormula 10a below:

Non-limiting examples of the compound of Formula 11 arebis(4-fluorophenyl)(phenyl)phosphine oxide, a compound represented byFormula 11a below, or a compound represented by Formula 12 below:

The polymer obtained using the above-described method may be a blockcopolymer, an alternating copolymer, or a random copolymer depending onthe linking status of the first repeating unit and the second repeatingunit.

According to another embodiment, a composite membrane includes any ofthe polymers according to the above-described embodiments.

The composite membrane including the above-described polymer may haveimproved thermal stability, improved tensile strength, improved strainat break, and improved conductivity characteristics.

The composite membrane may further include at least one compoundselected from compounds of Formulae 14 to 19. When the compositemembrane further includes at least one of the compounds of Formulae 14to 19, the at least one of the compounds of Formulae 14 to 19 or apolymer thereof may be involved in the polymerization of the polymer ofFormula 1 to form a polymerization product of the polymer of Formula 1and the at least one of the compounds of Formulae 14 to 19 or a polymerthereof. For example, at least one polymer selected from compounds ofFormulae 14 to 19 may be involved in the polymerization of the polymerof Formula 1 to form a polymerization product of the polymer of Formula1 and the at least one polymer selected from compounds of Formulae 14 to19.

As used herein, the terms “a polymerization product of a compositioncomprising the polymer including a first repeating unit represented byFormula 1 and at least one selected from compounds of Formulae 14 to 19”may indicate a cross-linked product of the polymer including the firstrepeating unit of Formula 1 and the at least one selected from compoundsof Formulae 14 to 19.

In Formula 14,

R₁, R₂, R₃, and R₄ may be each independently a hydrogen atom, asubstituted or unsubstituted C1-C20 alkyl group, a substituted orunsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, asubstituted or unsubstituted C6-C20 aryl group, a substituted orunsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC2-C20 heteroaryl group, a substituted or unsubstituted C2-C20heteroaryloxy group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic oxy group, asubstituted or unsubstituted C2-C20 heterocyclic group, a halogen atom,a hydroxy group, or a cyano group; and

R₅ may be a substituted or unsubstituted C1-C20 alkyl group, asubstituted or unsubstituted C1-C20 alkoxy group, a substituted orunsubstituted C2-C20 alkenyl group, a substituted or unsubstitutedC2-C20 alkynyl group, a substituted or unsubstituted C6-C20 aryl group,a substituted or unsubstituted C6-C20 aryloxy group, a substituted orunsubstituted C7-C20 arylalkyl group, a substituted or unsubstitutedC2-C20 heteroaryl group, a substituted or unsubstituted C2-C20heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocylic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group.

In Formula 15,

R₅′ may be a substituted or unsubstituted C1-C20 alkyl group, asubstituted or unsubstituted C1-C20 alkoxy group, a substituted orunsubstituted C2-C20 alkenyl group, a substituted or unsubstitutedC2-C20 alkynyl group, a substituted or unsubstituted C6-C20 aryl group,a substituted or unsubstituted C6-C20 aryloxy group, a substituted orunsubstituted C7-C20 arylalkyl group, a substituted or unsubstitutedC2-C20 heteroaryl group, a substituted or unsubstituted C2-C20heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocylic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group; and

R₆ may be selected from a substituted or unsubstituted C1-C20 alkylenegroup, a substituted or unsubstituted C2-C20 alkenylene group, asubstituted or unsubstituted C2-C20 alkynylene group, a substituted orunsubstituted C6-C20 arylene group, a substituted or unsubstitutedC2-C20 heteroarylene group, —C(═O)—, and —SO₂—.

In Formula 16,

A, B, C, D, and E may be carbon atoms; or

one or two of A, B, C, D, and E may be nitrogen atoms (N), and theremaining A, B, C, D, and E may be carbon atoms,

R₇ and R₈ may be linked to each other to form a ring, wherein the ringis a C6-C10 cycloalkyl group, a C3-C10 heteroaryl group, a fused C3-C10heteroaryl group, a C3-C10 heterocyclic group, or a fused C3-C10heterocyclic group.

In Formula 17,

A′ may be a substituted or unsubstituted C1-C20 heterocyclic group, asubstituted or unsubstituted C4-C20 cycloalkyl group, or a substitutedor unsubstituted C1-C20 alkyl group; and

R₉ to R₁₆ may be each independently a hydrogen atom, C1-C20 alkyl group,a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, aC1-C20 heteroaryl group, a C1-C20 heteroaryloxy group, a C4-C20cycloalkyl group, a C1-C20 heterocyclic group, a halogen atom, a cyanogroup, or a hydroxy group.

In Formula 18,

R₁₇ and R₁₈ may be each independently a C1-C20 alkyl group, a C1-C20alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, or a grouprepresented by Formula 8A below.

In Formulae 18 and 18a,

R₁₉ and R_(19′) may be each independently a hydrogen atom, a C1-C20alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20aryloxy group, a halogenated C6-C20 aryl group, a halogenated C6-C20aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group,a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 cycloalkyl group, a halogenated C4-C20cycloalkyl group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group.

In Formula 19,

at least two groups selected from R₂₀, R₂₁, and R₂₂ may be linked toeach other to form a group represented by Formula 19a below,

the remaining R₂₀, R₂₁, and R₂₂ may be each independently a hydrogenatom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group,a C6-C20 aryloxy group, a halogenated C6-C20 aryl group, a halogenatedC6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxygroup, a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group,

at least two adjacent groups selected from R₂₃, R₂₄, and R₂₅ may belinked to each other to form a group represented by Formula 19a below,and

the remaining R₂₃, R₂₄, and R₂₅ may be each independently a C1-C20 alkylgroup, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxygroup, a halogenated C6-C20 aryl group, a halogenated C6-C20 aryloxygroup, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group, ahalogenated C1-C20 heteroaryl group, a halogenated C1-C20 heteroaryloxygroup, a C4-C20 carbocyclic group, a halogenated C4-C20 carbocyclicgroup, a C1-C20 heterocyclic group, or a halogenated C1-C20 heterocyclicgroup.

In Formula 19a,

R₁′ may be a substituted or unsubstituted C1-C20 alkyl group, asubstituted or unsubstituted C1-C20 alkoxy group, a substituted orunsubstituted C2-C20 alkenyl group, a substituted or unsubstitutedC2-C20 alkynyl group, a substituted or unsubstituted C6-C20 aryl group,a substituted or unsubstituted C6-C20 aryloxy group, a substituted orunsubstituted C7-C20 arylalkyl group, a substituted or unsubstitutedC2-C20 heteroaryl group, a substituted or unsubstituted C2-C20heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocylic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group, and

* indicates a binding site to at least two adjacent groups of R₂₀, R₂₁,and R₂₂ in Formula 19, and a binding site to at least two adjacentgroups of R₂₃, R₂₄, and R₂₅ in Formula 19.

A composition for forming the composite membrane may include the polymerincluding a first repeating unit of Formula 1 and at least one selectedfrom compounds of Formulae 14 to 19.

An amount of the at least one selected from compounds of Formulae 14 to19 may be from about 5 parts to about 70 parts by weight, and in someembodiments, from about 20 parts to about 50 parts by weight, based on100 parts by weight of the polymer including the first repeating unit ofFormula 1.

When the amount of the at least one of the compounds of Formulae 14 to19 is within this range, a composite or composite membrane havingimproved physical characteristics may be obtained from the composition.

The composite may be a polymerization product of either the polymerincluding a first repeating unit of Formula 1 or a polymer including afirst repeating unit of Formula 1 and a second repeating unit of Formula2, and a polymer of at least one selected from compounds of Formulae 14to 19. This may be identified from infrared ray absorption spectra ornuclear magnetic resonance spectra of the polymerization product.

A composite membrane formed using the composite may have improvedthermal stability, improved conductivity, and improved mechanicalcharacteristics.

The composite membrane may be used as an electrolyte membrane.

According to another embodiment, a method of forming a compositemembrane is described below.

The polymer including a first repeating unit of Formula 1 or the polymerincluding a first repeating unit of Formula 1 and a second repeatingunit of Formula 2 may be mixed with a solvent to obtain a compositionfor forming the composite membrane, which may then be coated on asubstrate and thermally treated to obtain the composite membrane.

At least one selected from compounds of Formulae 14 to 19 may be addedinto the composition for forming the composite membrane.

The coating of the composition is not specifically limited, and may beperformed using dipping, spray coating, screen printing, coating with adoctor blade, Gravure coating, dip coating, roll coating, comma coating,silk screen, or a combination thereof.

In an embodiment, the coating of the composition may be performed byapplying the composition to a substrate, leaving the substrate at apredetermined temperature to allow the composition to uniformly spreadover the substrate, and shaping the composition in membrane form havinga predetermined thickness by using a coater, such as a doctor blade.

The mixing of the polymer and at least one of the compounds of Formulae14 to 19 is not specifically limited for example, in terms of the orderof adding the compounds, use of a solvent, and a type of the solvent.

During the mixing, a ball mill, for example, a planetary ball mill, maybe used to mix the components while grinding. The method of mixing isnot particularly critical and may be carried out by a variety of means,for example dispersion, blending, stirring, sonication, sparging,milling, shaking, centrifugal circulating pump mixing, blade mixing,impact mixing, jet mixing, homogenization, co-spraying, high sheermixing, single pass and multi-pass mixing, and the like.

The thermal treatment may be performed at a temperature of from roomtemperature (from about 20° C. to about 25° C.) to about 300° C., and insome embodiments, may be performed at about 150° C. When the thermaltreatment is performed within these temperature ranges, an electrolytemembrane with improved conductivity and uniform thickness may beattained without a reduction in mechanical strength.

The solvent may be dichloromethane, chloroform, toluene, chlorobenzene,methyl acetate, ethyl acetate, γ-butyrolactone, acetone, methyl ethylketone, cyclohexanone, ether, 1,2-dimethoxyethane (“DME”),1,2-diethoxyethane, tetrahydrofuran (“THF”), 1,4-dioxane, a chain-typecarbonate (such as dimethyl carbonate, ethyl methyl carbonate, diethylcarbonate, and dipropyl carbonate), a cyclic carbonate (such as ethylenecarbonate, propylene carbonate, and butylene carbonate), methanol,ethanol, water, dimethylsulfoxide (“DMSO”), N-methylpyrrolidone (“NMP”),N,N-dimethylacetamide (“DMA”), N,N-dimethylformamide (“DMF”), or thelike. A combination comprising at least one of the foregoing solventscan be used. Any suitable solvent available for these purposes in theart may be used.

An amount of the solvent may be from about 100 parts to about 2,000parts by weight, and in some embodiments, about 500 to 1,000 parts byweight based on 100 parts by weight of the polymer. When the amount ofthe solvent is within these ranges, the composition may have anappropriate solid content with an appropriate viscosity, which mayimprove the feasibility of the process of forming the composite membranefrom the composition.

In an embodiment, the composition may be coated on a substrate andthermally treated to form a film, which may then be separated from thesubstrate, thereby obtaining a composite membrane.

The substrate is not specifically limited. For example, the substratemay be any of a variety of supports, such as a glass substrate, arelease film, or an anode electrode.

Non-limiting examples of the release film are a polytetrafluoroethylenefilm, a polyvinylidenefluoride film, a polyethyleneterephthalate film,and a mylar film.

When used as an electrolyte membrane, the composite membrane may supplya phosphoric acid-based material to the electrolyte membrane. When thephosphoric acid-based material is supplied to the electrolyte membrane,a reaction temperature may be from about 30° C. to about 120° C., and inanother embodiment, may be at about 60° C.

The phosphoric acid-based material may be supplied to the electrolytemembrane in any of a variety of manners. For example, the electrolytemembrane may be immersed in the phosphoric acid-based material.

The electrolyte membrane prepared through the above-described processesmay have a thickness of about 1 μm to about 100 μm, and in someembodiments, may have a thickness of about 30 μm to about 90 μm. Thecomposite membrane may be formed as a thin film having a thickness asdefined above.

The electrolyte membrane may be used as a non-humidified protonconductor, and may be used in a fuel cell operating in low-temperature,high-humidity conditions, or in high-temperature, non-humidifiedconditions. The term “high temperature” indicates a temperature of about120° C. to about 400° C.; however, the high temperature is notparticularly limited.

According to an aspect, there is provided a fuel cell that includes theabove-described composite membrane as an electrolyte membrane disposedbetween a cathode and an anode. The fuel cell may have high efficiencycharacteristics because it exhibits high proton conductivity andlifetime characteristics at high temperatures in non-humidifiedconditions.

The fuel cell may be used for any purpose. For example, the fuel cellmay be used to implement a solid oxide fuel cell (“SOFC”), a protonexchange membrane fuel cell (“PEMFCs”), and the like.

FIG. 1 is a perspective exploded view of a fuel cell 1 according to anembodiment. FIG. 2 is a cross-sectional diagram of a membrane-electrodeassembly (“MEA”) that forms the fuel cell 1 of FIG. 1.

Referring to FIG. 1, the fuel cell 1 according to the present embodimentincludes two unit cells 11 that are supported by a pair of holders 12.Each unit cell 11 includes an MEA 10, and bipolar plates 20 disposed onlateral sides of the MEA 10. Each bipolar plate 20 includes a conductivemetal, carbon or the like, and operates as a current collector, whileproviding oxygen and fuel to the catalyst layers of the correspondingMEA 10.

Although only two unit cells 11 are shown illustrated in FIG. 1, thenumber of unit cells 11 is not limited to two and the fuel cell 1 mayhave several tens or hundreds of unit cells 11, depending on therequired properties of the fuel cell 1.

As shown in FIG. 2, the MEA 10 includes an electrolyte membrane 100,catalyst layers 110 and 110′ disposed on lateral sides of theelectrolyte membrane 100, and first gas diffusion layers 121 and 121′respectively stacked on the catalyst layers 110 and 110′, and second gasdiffusion layers 120 and 120′ respectively stacked on the first gasdiffusion layers 121 and 121′.

The electrolyte membrane 100 may be a composite electrode according tothe embodiments.

The catalyst layers 110 and 110′ respectively operate as a fuelelectrode and an oxygen electrode, each including a catalyst and abinder therein. The catalyst layers 110 and 110′ may further include amaterial that may increase the electrochemical surface area of thecatalyst.

The first gas diffusion layers 121 and 121′ and the second gas diffusionlayers 120 and 120′ may each be formed of a material such as, forexample, carbon sheet or carbon paper. The first gas diffusion layers121 and 121′ and the second gas diffusion layers 120 diffuse oxygen andfuel supplied through the bipolar plates 20 into the entire surfaces ofthe catalyst layers 110 and 110′.

The fuel cell 1 including the MEA 10 operates at a temperature of, forexample, about 1,250° C. to about 3,000° C. Fuel such as hydrogen issupplied through one of the bipolar plates 20 into a first catalystlayer, and an oxidant such as oxygen is supplied through the otherbipolar plate 20 into a second catalyst layer. Then, hydrogen isoxidized into protons in the first catalyst layer, and the protonsmigrate to the second catalyst layer through the electrolyte membrane 4.Then, the protons electrochemically react with oxygen in the secondcatalyst layer to produce water and electrical energy. Hydrogen producedfrom reformation of hydrocarbons or alcohols may be supplied as thefuel. Oxygen as the oxidant may be supplied in the form of air.

Hereinafter, a method of manufacturing a fuel cell using the electrolytemembrane according to an embodiment will be described.

Electrodes for a fuel cell that each includes a catalyst layercontaining a catalyst and a binder may be used.

The catalyst may be platinum (Pt), an alloy or a mixture of platinum(Pt) and at least one metal selected from gold (Au), palladium (Pd),rhodium (Ru), iridium (Ir), ruthenium (Ru), tin (Sn), molybdenum (Mo),cobalt (Co), and chromium (Cr). The Pt, the alloy, or the mixture may besupported on a carbonaceous support. For example, the catalyst may be atleast one metal selected from Pt, a PtCo alloy, and a PtRu alloy. Thesemetals may be supported on a carbonaceous support.

The binder may be at least one of a vinylidenefluoride/hexafluoropropylene copolymer, poly(vinylidenefluoride)(“PVDF”), polyacrylonitrile, polymethylmethacrylate,polytetrafluoroethylene, polyvinyl chloride, polyvinyl pyrrolidone,polypropylene, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropylcellulose, diacetyl cellulose, a styrene butadiene rubber polymer, atetrafluoroethylene-hexafluoroethylene copolymer, and perfluoroethylene.A combination including at least one of the foregoing binders can beused. Any suitable binder available for these purposes in the art may beused. The amount of the binder may be in the range of about 0.001 toabout 0.5 parts by weight, and in some embodiments about 0.01 to about0.5 parts by weight based on 1 part by weight of the catalyst. When theamount of the binder is within this range, the electrode catalyst layermay have strong binding ability to the support.

Any of the electrolyte membranes according to the embodiments includingthe composite may be disposed between the two electrodes to manufacturethe fuel cell.

In some embodiments, the composite prepared from a composition includinga polymer having a first repeating unit of Formula 1 may be used to forman electrode for a fuel cell.

The composition may further include at least one selected from compoundsrepresented by Formulae 14 to 19 above.

An amount of the at least one compound selected from compounds ofFormulae 14 to 19 may be from about 5 parts to about 70 parts by weight,in some embodiments about 10 to about 70 parts by weight, and in otherembodiments about 10 to about 50 parts by weight based on 100 parts byweight of the polymer including the first repeating unit of Formula 1.

According to an embodiment, a method of forming an electrode for a fuelcell may involve dispersing a catalyst in a third solvent to obtain adispersion.

The third solvent may be dimethylsulfoxide (“DMSO”), N-methylpyrrolidone(“NMP”), N,N-dimethylformamide (“DMF”), N, N-dimethylacetamide (“DMA”),dichloromethane, chloroform, toluene, chlorobenzene, methyl acetate,ethyl acetate, γ-butyrolactone, acetone, methyl ethyl ketone,cyclohexanone, ether, 1,2-dimethoxyethane (“DME”), 1,2-diethoxyethane,tetrahydrofuran (“THF”), 1,4-dioxane, a chain-type carbonate (such asdimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, anddipropyl carbonate), a cyclic carbonate (such as ethylene carbonate,propylene carbonate, and butylene carbonate), methanol, ethanol, andwater, or the like. A combination comprising at least one of theforegoing solvents can be used. Any suitable material available forthese purposes in the art may be used. An amount of the third solventmay be from about 100 parts to about 2,000 parts, and in someembodiments about 500 to about 1,000 parts by weight based on 100 partsby weight of the catalyst.

The polymer including the first repeating unit of Formula 1, or amixture of the polymer including the first repeating unit of Formula 1and at least one selected from compounds of Formulae 14 to 19 may beadded to the dispersion, and then mixed together while stirring toobtain a composition for forming an electrode catalyst layer. A bindermay be further added to the composition.

The composition for an electrode catalyst layer may be coated on thesurface of a carbon support, thereby completing formation of theelectrode. Herein, the carbon support may be fixed on a glass substrateto facilitate the coating. The coating method is not particularlylimited, but examples of the coating method may be coating using adoctor blade, bar coating, and screen printing.

The coating of the composition for forming the electrode catalyst layermay be followed by thermal treatment, which may be performed at atemperature of from about 20° C. to about 150° C.

The electrode for fuel cells as a final product may include a compositeas a polymerization product of the polymer including a first repeatingunit of Formula 1. Alternatively, the electrode for fuel cells as afinal product may include a composite as a polymerization product of thepolymer including a first repeating unit of Formula 1 and at least oneof the compounds of Formulae 14 to 19.

The polymerization product may be obtained through the above-describedthermal treatment or during operation of a battery including theabove-described electrode as a result of the polymerization of thepolymer including the first repeating unit of Formula 1 and at least oneselected from compounds of Formulae 14 to 19.

For example, the polymerization reaction may include a cross-linkingreaction between the polymer including a first repeating unit of Formula1 and at least one selected from compounds of Formulae 14 to 19.Alternatively, the polymerization reaction may include may include across-linking reaction between the polymer including a first repeatingunit of Formula 1 and a polymer of at least one selected from compoundsof Formulae 14 to 19.

Substituents in the formulae above may be defined as follows.

As used herein, the term “alkyl” indicates a completely saturated,branched or unbranched (or a straight or linear) hydrocarbon having thespecified number of carbon atoms.

Non-limiting examples of the “alkyl” group include methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, isopentyl,neopentyl, iso-amyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl,2,3-dimethylpentyl, and n-heptyl.

At least one hydrogen atom of the alkyl group may be substituted with ahalogen atom, a C1-C20 alkyl group substituted with a halogen atom (forexample, —CCF₃, —CHCF₂, —CH₂F, —CCl₃, and the like), a C1-C20 alkoxygroup, a C2-C20 alkoxyalkyl group, a hydroxyl group (—OH), a nitro group(—NO₂), a cyano group (—CN), an amino group (—NRR′, wherein R and R′ areeach independently hydrogen or a C1-C10 alkyl group), an amido group(—C(═O)NRR′, wherein R and R′ are independently hydrogen or a C1-C10alkyl group), an amidino group (—C(═NH)NRR′ wherein R and R′ areindependently hydrogen or a C1-C10 alkyl group), a hydrazine group(—NHNRR′, wherein R and R′ are independently hydrogen or a C₁-C₁₀ alkylgroup), a hydrazone group (—CR═NHNR′R″, wherein R, R′ and R″ areindependently hydrogen or a C1-C10 alkyl group), a carboxyl group(—CO₂H) or a salt thereof, a sulfonyl group, a sulfamoyl group, asulfonic acid group (—SO₃H) or a salt thereof, a phosphoric acid(—P(═O)(OH)₂) or a salt thereof, a C1-C20 alkyl group, a C2-C20 alkenylgroup, a C2-C20 alkynyl group, a C1-C20 heteroalkyl group, a C6-C20 arylgroup, a C6-C20 arylalkyl group, a C6-C20 heteroaryl group, a C7-C20heteroarylalkyl group, a C6-C20 heteroaryloxy group, a C6-C20heteroaryloxyalkyl group, or a C6-C20 heteroarylalkyl group.

The term “halogen atom” indicates fluorine, bromine, chloride, iodine,and the like.

The term “C1-C20 alkyl group substituted with a halogen atom” indicatesa C1-C20 alkyl group substituted with at least one halogen atom.Non-limiting examples of the C1-C20 alkyl group substituted with ahalogen atom include polyhaloalkyls including monohaloalkyl,dihaloalkyl, or perhaloalkyl.

Monohaloalkyls indicate alkyl groups including one iodine, bromine,chloride or fluoride. Dihaloalkyls indicate alkyl groups including twoidentical or different halogen atoms. Perhaloalkyls indicate alkylgroups wherein all hydrogen atoms are replaced with identical ordifferent halogen atoms.

As used herein, the term “alkoxy” represents “alkyl-O-”, wherein thealkyl is the same as described above, and which has the specified numberof carbon atoms. Non-limiting examples of the alkoxy group includemethoxy, ethoxy, n-propoxy, 2-propoxy, n-butoxy, iso-butoxy, t-butoxy,pentyloxy, hexyloxy, cyclopropoxy, and cyclohexyloxy. At least onehydrogen atom of the alkoxy group may be substituted with substituentsthat are the same as those recited above in conjunction with the alkylgroup.

As used herein, the term “alkoxyalkyl” indicates an alkyl group with analkoxy substituent as recited above, and which has the specified numberof carbon atoms. At least one hydrogen atom of the alkoxyalkyl group maybe substituted with substituents that are the same as those recitedabove in conjunction with the alkyl group. As defined above, the term“alkoxyalkyl” indicates unsubstituted or substituted alkoxyalkylmoieties.

As used herein, the term “alkenyl” indicates a branched or unbranchedhydrocarbon with at least one carbon-carbon double bond having thespecified number of carbon atoms. Non-limiting examples of the alkenylgroup include vinyl, aryl, butenyl, isopropenyl, and isobutenyl. Atleast one hydrogen atom in the alkenyl group may be substituted with asubstituent that is the same as that recited above in conjunction withthe alkyl group.

As used herein, the term “alkynyl” indicates a branched or unbranchedhydrocarbon with at least one carbon-carbon triple bond having thespecified number of carbon atoms. Non-limiting examples of the “alkynyl”group include ethynyl, butynyl, isobutynyl, and isopropynyl.

At least one hydrogen atom of the “alkynyl” group may be substitutedwith substituents that are the same as those recited above inconjunction with the alkyl group.

As used herein, the term “aryl”, which is used alone or in combination,indicates an aromatic hydrocarbon containing at least one ring andhaving the specified number of carbon atoms.

The term “aryl” may be construed as including a group with an aromaticring fused to at least one cycloalkyl ring.

Non-limiting examples of the “aryl” group include phenyl, naphthyl, andtetrahydronaphthyl.

At least one hydrogen atom of the “aryl” group may be substituted withsubstituents that are the same as those recited above in conjunctionwith the alkyl group.

As used herein, the term “arylalkyl” indicates an alkyl groupsubstituted with an aryl group. Non-limiting examples of the arylalkylgroup include benzyl (C₆H₅CH₂—) or phenylethyl (C₆H₅CH₂CH₂—).

As used herein, the term “aryloxy” indicates “—O-aryl”, wherein the arylis the same as described above, and which has the specified number ofcarbon atoms. An example of the aryloxy group is phenoxy. At least onehydrogen atom of the “aryloxy” group may be substituted withsubstituents that are the same as those recited above in conjunctionwith the alkyl group. An example of the aryloxy group is phenoxy.

As used herein, the term “heteroaryl” indicates a monocyclic or bicyclicorganic compound including at least one heteroatom selected fromnitrogen (N), oxygen (O), phosphorous (P), and sulfur (S), wherein theremaining ring atoms are all carbon. The heteroaryl group may include,for example, one to five heteroatoms, and in some embodiments, mayinclude a five- to ten-membered ring.

In the heteroaryl group, S or N may be present in various oxidizedforms.

Non-limiting examples of the monocyclic heteroaryl group includethienyl, furyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,isothiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl,1,3,4-oxadiaxolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl,1,2,5-thiadiazolyl, 1,3,4-thiazolyl, isothiazol-3-yl, isothiazol-4-yl,isothiazol-5-yl, oxazol-2-yl, oxazol-4-yl, oxazol-5-yl, isoxazol-3-yl,isoxazol-4-yl, isoxazol-5-yl, 1,2,4-triazol-3-yl, 1,2,4-triazol-5-yl,1,2,3-triazol-4-yl, 1,2,3-triazol-5-yl, tetrazolyl, pyrid-2-yl,pyrid-3-yl, 2-pyrazin-2-yl, pyrazin-4-yl, pyrazin-5-yl,2-pyrimidin-2-yl, 4-pyrimidin-2-yl, and 5-pyrimidin-2-yl.

The term “heteroaryl” may indicate a heteroaromatic ring fused to atleast one of an aryl group, a cycloaliphatic group, and a heterocyclicgroup.

Non-limiting examples of the bicyclic heteroaryl group include indolyl,isoindolyl, indazolyl, indolizinyl, purinyl, quinolizinyl, quinolinyl,isoquinolinyl, cinnolinyl, phthalazinyl, naphthyridinyl, quinazolinyl,quinaxalinyl, phenanthridinyl, phenathrolinyl, phenazinyl,phenothiazinyl, phenoxazinyl, benzisoquinolinyl, thieno[2,3-b]furanyl,furo[3,2-b]-pyranyl, 5H-pyrido[2,3-d]-o-oxazinyl,1H-pyrazolo[4,3-d]oxazolyl, 4H-imidazo[4,5-d]thiazolyl,pyrazino[2,3-d]pyridazinyl, imidazo[2,1-b]thiazolyl,imidazo[1,2-b][1,2,4]triazinyl, 7-benzo[b]thienyl, benzoxazolyl,benzimidazolyl, benzothiazolyl, benzoxapinyl, benzoxazinyl,1H-pyrrolo[1,2-b][2]benzazapinyl, benzofuryl, benzothiophenyl,benzotriazolyl, pyrrolo[2,3-b]pyridinyl, pyrrolo[3,2-c]pyridinyl,pyrrolo[3,2-b]pyridinyl, imidazo[4,5-b]pyridinyl,imidazo[4,5-c]pyridinyl, pyrazolo[4,3-d]pyridinyl,pyrazolo[4,3-c]pyridinyl, pyrazolo[3,4-c]pyridinyl,pyrazolo[3,4-d]pyridinyl, pyrazolo[3,4-b]pyridinyl,imidazo[1,2-a]pyridinyl, pyrazolo[1,5-a]pyridinyl,pyrrolo[1,2-b]pyridazinyl, imidazo[1,2-c]pyrimidinyl,pyrido[3,2-d]pyrimidinyl, pyrido[4,3-d]pyrimidinyl,pyrido[3,4-d]pyrimidinyl, pyrido[2,3-d]pyrimidinyl,pyrido[2,3-b]pyrazinyl, pyrido[3,4-b]pyrazinyl,pyrimido[5,4-d]pyrimidinyl, pyrazino[2,3-b]pyrazinyl, andpyrimido[4,5-d]pyrimidinyl.

At least one hydrogen atom of the “heteroaryl” group may be substitutedwith substituents that are the same as those recited above inconjunction with the alkyl group.

As used herein, the term “heteroarylalkyl” group indicates an alkylgroup substituted with a heteroaryl group, wherein the alkyl andheteroaryl groups are the same as described above, and which has thespecified number of carbon atoms. An example of the heteroarylalkylgroup is 2-pyridylmethyl.

As used herein, the term “heteroaryloxy” group indicates a“—O-heteroaryl moiety”, wherein the heteroaryl is the same as describedabove, and which has the specified number of carbon atoms. At least onehydrogen atom of the heteroaryloxy group may be substituted withsubstituents that are the same as those recited above in conjunctionwith the alkyl group. An example of the heteroaryloxy group may be2-pyridyloxy.

As used herein, the term “heteroaryloxyalkyl” group indicates an alkylgroup substituted with a heteroaryloxy group, wherein the alkyl andheteroaryloxy are the same as described above, and which has thespecified number of carbon atoms. At least one hydrogen atom of theheteroaryloxyalkyl group may be substituted with substituents that arethe same as those recited above in conjunction with the alkyl group. Anexample of the heteroaryloxy group is 2-pyridyloxymethyl.

As used herein, the term “carbocyclic” group indicates a saturated orpartially unsaturated non-aromatic monocyclic, bicyclic or tricyclichydrocarbon group having a specified number of carbon atoms.

Non-limiting examples of the monocyclic hydrocarbon group includecyclopentyl, cyclopentenyl, cyclohexyl, and cyclohexenyl.

Non-limiting examples of the bicyclic hydrocarbon group include bornyl,decahydronaphthyl, bicyclo[2.1.1]hexyl, bicyclo[2.2.1]heptyl,bicyclo[2.2.1]heptenyl, and bicyclo[2.2.2]octyl.

An example of the tricyclic hydrocarbon group is adamantyl.

At least one hydrogen atom of the “carbocyclic group” may be substitutedwith substituents that are the same as those recited above inconjunction with the alkyl group.

As used herein, the term “heterocyclic” indicates a five- toten-membered ring group including a heteroatom such as N, S, P, or O,and having a specified number of carbon atoms. An example of theheterocyclic group is N-piperidyl. At least one hydrogen atom in theheterocyclic group may be substituted with substituents that are thesame as those recited above in conjunction with the alkyl group.

As used herein, the term “heterocyclic oxy” indicates “—O-hetero ring”having a specified number of carbon atoms. At least one hydrogen atom ofthe heterocyclic oxy group may be substituted with substituents that arethe same as those recited above in conjunction with the alkyl group. Anexample of the heterocyclic oxy group may be 4-piperidinoxy-.

As used herein, the term “sulfonyl” indicates R″—SO₂—, wherein R″ is ahydrogen atom, alkyl, aryl, heteroaryl, aryl-alkyl, heteroaryl-alkyl,alkoxy, aryloxy, cycloalkyl, or a heterocyclic group.

As used herein, the term “sulfamoyl” group indicates H₂NS(O₂)—,alkyl-NHS(O₂)—, (alkyl)₂NS(O₂)-aryl-NHS(O₂)—, alkyl-(aryl)-NS(O₂)—,(aryl)₂NS(O)₂, heteroaryl-NHS(O₂)—, (aryl-alkyl)-NHS(O₂)—, or(heteroaryl-alkyl)-NHS(O₂)—.

At least one hydrogen atom of the sulfamoyl group may be substitutedwith substituents that are the same as those described above inconjunction with the alkyl group.

As used herein, the term “amino group” indicates a group with a nitrogenatom covalently bonded to at least one carbon or hetero atom and havinga specified number of carbon atoms. The amino group may indicate, forexample, —NH₂ and substituted moieties, as indicated above.

As used herein, the term “amino group” also indicates an “alkylaminogroup” with nitrogen bound to at least one additional alkyl group, and“arylamino” and “diarylamino” groups with at least one or two nitrogenatoms bound to a selected aryl group.

As used herein, the terms “arylalkyl”, “arylalkyl oxy”,“heteroarylalkyl”, “heteroarylalkyl oxy”, “carbocyclic alkyl”, and“carbocyclic alkyloxy” indicate groups derived from an aryl group, anaryloxy group, a heteroaryl group, a heteroaryloxy group, a carbocyclicgroup, and a carbocyclic oxy group, respectively, and further includingan alkyl group. These groups may be substituted with substituents thatare the same as those described above in conjunction with the alkylgroup.

As used herein, the terms “arylalkylene”, “arylene oxy”, “arylalkyleneoxy”, “heteroarylene”, “heteroarylalkylene”, “heteroarylene oxy”,“heteroarylalkylene oxy”, “carbocyclic alkylene”, and “carbocyclicalkylene oxy” indicate divalent organic groups derived from an arylalkylgroup, an aryloxy group, an arylalkyl oxy group, a heteroaryl group, aheteroarylalkyl group, a heteroaryloxy group, a heteroarylalkyl oxygroup, a carbocyclic alkyl group, and a carbocyclic alkyloxy group,respectively. These groups may be substituted with substituents that arethe same as those described above in conjunction with the alkyl group.

As used herein, the terms “alkylene”, “arylene oxy”, and“heteroalkylene”, indicate divalent groups derived from an alkyl group,an aryl group, and a heteroaryl group, respectively. These groups may besubstituted with substituents that are the same as those described abovein conjunction with the alkyl, aryl, or heteroaryl groups.

Hereinafter, the present inventive concept will be described in detailwith reference to the following examples. However, these examples arefor illustrative purposes only and do intend to limit the scope of thepresent disclosure.

Preparation Example 1 Synthesis of Polymer of Formula 6a

1 mmol (0.62 g) of bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphineoxide, 9 mmol (2.83 g) of bis(4-fluorophenyl)(phenyl)phosphine oxide,and 10 mmol (1.86 g) of 4,4′-dihydroxybiphenyl(p,p′-biphenol) were addedinto a 3-necked reaction flask equipped with a mechanical stirrer and adean stark trap.

20 mmol (2.76 g) of K₂CO₃, 20 mL of NMP, 10 mL of toluene were put intothe reaction flask, followed by azeotropic distillation at about 150° C.for about 2 hours and removing toluene.

The temperature of the reaction flask was increased to about 180° C. forfurther reaction for about 20 hours, followed by precipitation two tothree times with deionized water and isopropyl alcohol for purification.The resulting purified product was dried in a vacuum oven to obtain apolymer of Formula 6a.

A structure of the polymer was identified by nuclear magnetic resonance(“NMR”) analysis.

The polymer had a number average molecular weight of about 80,000 and aweight average molecular weight of about 250,000.

Preparation Example 2 Synthesis of Polymer of Formula 6b

A polymer of Formula 6b was synthesized in the same manner as inPreparation Example 1, except that 3 mmol (1.86 g) ofbis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide and 7 mmol(2.20 g) of bis(4-fluorophenyl)(phenyl)phosphine oxide instead of 1 mmol(0.62 g) of bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxideand 9 mmol (2.83 g) of bis(4-fluorophenyl)(phenyl)phosphine oxide wereused.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 65,000 and aweight average molecular weight of about 220,000.

Preparation Example 3 Synthesis of Polymer of Formula 6c

A polymer of Formula 6 (a=0.5, b=0.5) was synthesized in the same manneras in Preparation Example 1, except that 5 mmol (3.1 g) ofbis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide and 5 mmol(1.57 g) of bis(4-fluorophenyl)(phenyl)phosphine oxide instead of 1 mmol(0.62 g) of bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxideand 9 mmol (2.83 g) of bis(4-fluorophenyl)(phenyl)phosphine oxide wereused.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 60,000 and aweight average molecular weight of about 200,000.

Preparation Example 4 Synthesis of Polymer of Formula 7A

A polymer of Formula 7A was synthesized in the same manner as inPreparation Example 1, except that 9 mmol of a compound represented byFormula 11a below instead of 9 mmol ofbis(4-fluorophenyl)(phenyl)phosphine oxide was used:

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 100,000 and aweight average molecular weight of about 420,000.

Preparation Example 5 Synthesis of Polymer of Formula 7B

A polymer of Formula 7B was synthesized in the same manner as inPreparation Example 4, except that 7 mmol of the compound represented byFormula 11a and 3 mmol ofbis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide and instead of9 mmol of the compound represented by Formula 11a and 1 mmol ofbis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide and were used:

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 85,000 and aweight average molecular weight of about 350,000.

Preparation Example 6 Synthesis of Polymer of Formula 7C

A polymer of Formula 7C was synthesized in the same manner as inPreparation Example 4, except that 5 mmol of the compound of Formula 11aand 5 mmol of bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxideinstead of 9 mmol of the compound represented by Formula 11a and 1 mmolof bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide were used.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 60,000 and aweight average molecular weight of about 200,000.

Preparation Example 7 Synthesis of Polymer of Formula 7d

A polymer of Formula 7d was synthesized in the same manner as inPreparation Example 2, except that 7 mmol of the compound of Formula 11aand 10 mmol of a compound of Formula 10a instead of 3 mmol ofbis(4-fluorophenyl)(phenyl)phosphine oxide and 10 mmol of4,4′-dihydroxybiphenyl were used.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 50,000 and aweight average molecular weight of about 210,000.

Preparation Example 8 Synthesis of Polymer of Formula 7e

A polymer of Formula 7e was synthesized in the same manner as inPreparation Example 7, except that 5 mmol of the compound of Formula 11aand 5 mmol of bis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxideinstead of 7 mmol of the compound of Formula 11a and 3 mmol ofbis(4-fluoro-3-sulfophenyl)(3-sulfophenyl)phosphine oxide were used.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 30,000 and aweight average molecular weight of about 160,000.

Preparation Example 9 Synthesis of Polymer of Formula 8a

A polymer of Formula 8a was synthesized in the same manner as inPreparation Example 2, except that 7 mmol of the compound of Formula 11binstead of 7 mmol of bis(4-fluorophenyl)(phenyl)phosphine oxide wereused.

A structure of the polymer was identified by NMR analysis.

The polymer had a number average molecular weight of about 70,000 and aweight average molecular weight of about 230,000.

Comparative Preparation Example 1 Preparation of Polymer of Formula 13

3 mmol of a compound of Formula 12, 7 mmol of a compound of Formula 11a,and 1.86 g (10 mmol) of 4,4′-dihydroxybiphenyl(p,p′-biphenol) were addedinto a 3-necked reaction flask equipped with a mechanical stirrer and adean stark trap.

20 mmol (2.76 g) of K₂CO₃, 20 mL of NMP, 10 mL of toluene were put intothe reaction flask, followed by azeotropic distillation at about 150° C.for about 2 hours and removing toluene.

The temperature of the reaction flask was increased to about 180° C. forfurther reaction for about 20 hours, followed by precipitation two tothree times with deionized water and isopropyl alcohol for purification.The resulting purified product was dried in a vacuum oven to obtain apolymer of Formula 13.

A polymer of Formula 13 having a number average molecular weight ofabout 140,000 and a weight average molecular weight of about 950,000 wasprepared as follows.

Example 1 Preparation of Electrolyte Membrane

2 g of the polymer of Preparation Example 1 was dissolved in 18 ml ofN,N-dimethylacetamide (“DMA”) to obtain an electrolyte membrane formingcomposition, which was then cast on to a glass substrate and dried atabout 60° C. to form an electrolyte membrane.

Examples 2 to 9 Preparation of Electrolyte Membrane

An electrolyte membrane was formed in the same manner as in Example 1,except that the polymer of Preparation Example 2-9 instead of thepolymer of Preparation Example 1 was used.

Comparative Example 1 Preparation of Electrolyte Membrane

An electrolyte membrane was formed in the same manner as in Example 1,except that the polymer of Comparative Preparation Example 1 instead ofthe polymer of Preparation Example 1 was used.

Manufacture Examples 1-9 Manufacture of Fuel Cell

Fuel cells were manufactured by disposing each of the electrolytemembranes of Examples 1 to 9 between a cathode and anode.

The cathode and anode were manufactured as follows for use in each cell.

4.5 g of a 10 percent by weight (weight %) NAFION (available from DuPont Inc.) aqueous dispersion was dropwise added to a solution of 50weight % of PtCo supported on carbon (“PtCo/C”) in 3 ml of isopropylalcohol, followed by mechanical agitation to prepare a composition forforming a cathode catalyst layer.

The composition for forming a cathode catalyst layer was coated on onesurface of carbon paper to manufacture the cathode.

The anode was manufactured in the same manner as in the manufacture ofthe cathode, except that, instead of PtCo/C in the composition forforming a cathode catalyst layer, PtRu/C (50 weight % of PtRu supportedon carbon) was used.

To test the performance of each fuel cell, non-humidified H₂ and O₂ weresupplied to the anode and cathode at about 50 cubic centimeters (“ccm”)and about 100 ccm, respectively, and the fuel cell was operated at about100° C. to about 200° C. in non-humidified conditions.

Comparative Manufacture Example 1 Manufacture of Fuel Cell

A fuel cell was manufactured in the same manner as in ManufactureExample 1, except that the electrolyte membrane of Comparative Example 1instead of the electrolyte membrane of Example 1 was used.

Evaluation Example 1 Nuclear Magnetic Resonance (NMR) Analysis

Proton nuclear magnetic resonance spectra (“¹H-NMR”) of the polymers ofPreparation Examples 1 to 8 are shown in FIGS. 5 to 12.

The structures of the polymers of Preparation Examples 1 to 8 may beidentified from the NMR spectra of FIGS. 5 to 12.

Evaluation Example 2 Thermogravimetric Analysis (TGA)

Thermal stabilities of the electrolyte membranes of Examples 4 to 6 andComparative Example 1 were evaluated using a differential scanningcalorimeter (DSC, Q5000IR, available from TA Instruments) as athermogravimetric analyzer (“TGA”) at a heating rate of about 10 degreesCentigrade per minute (“t/min”).

The evaluation results are shown in FIG. 3.

Referring to FIG. 3, an onset decomposition temperature of theelectrolyte membranes of Examples 4 to 6 was higher than that of theelectrolyte membrane of Comparative Example 1, and contained a largeramount of actual carbon remaining after heating to about 800° C., whichindicates having better thermal stability than the electrolyte membranesof Comparative Example 1.

Evaluation Example 3 Analysis of Mechanical Characteristics ofElectrolyte Membrane

Tensile strengths and strains at break of the electrolyte membranes ofExamples 1 and 5 and Comparative Example 1 were measured using auniversal testing machine (UTM, Lloyd LR-10K). Test samples wereprepared based on ASTM standard D638 (Type V specimens).

The results of the tensile strength and strain at break tests are shownin Table 1 below.

Table 1

Example Tensile Strength (MPa) Strain at break (%) Example 1 81.9 ± 1.25.9 ± 1.0 Example 5 40.4 ± 2.1 4.2 ± 0.5 Comparative Example 1 — 32.3 ±10.2

Referring to Table 1, the electrolyte membranes of Examples 1 and 5 hada tensile strength of about 20 megapascal (“MPa”) or greater, whichsatisfies stiffness requirements for membrane-electrode assemblies. Theelectrolyte membranes of Examples 1 and 2 were smaller in stain atbreak, compared to the electrolyte membranes of Comparative Example 1,indicating that the electrolyte membranes of Examples 1 and 2 are lessdeformable and more stable to maintain dimensional stability after beingassembled into cells. The results of Table 1 indicate that theelectrolyte membranes of Examples 1 and 5 have improved mechanicalstabilities.

Evaluation Example 4 Conductivity Test

After being immersed in a 2N aqueous sulfuric acid solution at about 90°C. for about 4 hours, the electrolyte membranes of Example 6 andComparative Example 1 were removed therefrom, and rinsed with deionizedwater to remove excess sulfuric acid, followed by drying to completelyremove the water and conductivity measurement at about 120° C. atdifferent relative humidity conditions. The results are shown in FIG. 4.

The conductivity measurement was performed using a 4-pointprobe-in-plane method in a Bekktec equipment at different relativehumidity conditions, hydrogen (H₂) (flow rate: about 1,000 standardcubic centimeter per minute (“SCCM”)) conditions at about 120° C.Referring to FIG. 4, the electrolyte membrane of Example 6 was found tohave higher conductivities in high-temperature, lower humidityconditions, compared to the electrolyte membrane of Comparative Example1.

As described above, according to the above embodiments, a compositemembrane with improved thermal stability, improved mechanicalcharacteristics, and improved ionic conductivity may be manufacturedusing a polymer including a repeating unit of Formula 1 or compositeprepared from the polymer. A fuel cell with higher efficiency may bemanufactured using the composite membrane.

It should be understood that the exemplary embodiments described thereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

What is claimed is:
 1. A composite, which is a polymerization product ofa composition comprising: a polymer comprising a first repeating unitrepresented by Formula 1:

wherein, in Formula 1, at least one of R₁ to R₁₃ is a proton-conductinggroup, and the remaining R₁ to R₁₃ are each independently selected froma hydrogen atom, a substituted or unsubstituted C1-C40 alkyl group, asubstituted or unsubstituted C1-C40 alkoxy group, a substituted orunsubstituted C2-C40 alkenyl group, a substituted or unsubstitutedC2-C40 alkynyl group, a substituted or unsubstituted C6-C40 aryl group,a substituted or unsubstituted C7-C40 arylalkyl group, a substituted orunsubstituted C6-C40 aryloxy group, a substituted or unsubstitutedC2-C40 heteroaryl group, a substituted or unsubstituted C3-C40heteroarylalkyl group, a substituted or unsubstituted C2-C40heteroaryloxy group, a substituted or unsubstituted C4-C40 carbocyclicgroup, a substituted or unsubstituted C5-C40 carbocyclic alkyl group, asubstituted or unsubstituted C4-C40 carbocyclic oxy group, a substitutedor unsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group, and Ar₁ is a substituted or unsubstitutedC6-C40 arylene group, a substituted or unsubstituted C7-C40 arylalkylenegroup, a substituted or unsubstituted C6-C40 arylene oxy group, asubstituted or unsubstituted C7-C40 arylalkylene oxy group, asubstituted or unsubstituted C2-C40 heteroarylene group, a substitutedor unsubstituted C3-C40 heteroarylalkylene group, a substituted orunsubstituted C2-C40 heteroarylene oxy group, a substituted orunsubstituted C2-C40 heteroarylalkylene oxy group, a substituted orunsubstituted C4-C40 carbocyclic group, a substituted or unsubstitutedC5-C40 carbocyclic alkylene group, a substituted or unsubstituted C4-C40carbocyclic oxy group, or a substituted or unsubstituted C4-C40carbocyclic alkylene oxy group; and at least one selected from compoundsrepresented by Formulae 14 to 19:

wherein, in Formula 14, R₁, R₂, R₃, and R₄ are each independently ahydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, asubstituted or unsubstituted C1-C20 alkoxy group, a substituted orunsubstituted C2-C20 alkenyl group, a substituted or unsubstitutedC2-C20 alkynyl group, a substituted or unsubstituted C6-C20 aryl group,a substituted or unsubstituted C6-C20 aryloxy group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C4-C20carbocyclic group, a substituted or unsubstituted C4-C20 carbocyclic oxygroup, a substituted or unsubstituted C2-C20 heterocyclic group, ahalogen atom, a hydroxy group, or a cyano group; and R₅ is a substitutedor unsubstituted C1-C20 alkyl group, a substituted or unsubstitutedC1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenylgroup, a substituted or unsubstituted C2-C20 alkynyl group, asubstituted or unsubstituted C6-C20 aryl group, a substituted orunsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC7-C20 arylalkyl group, a substituted or unsubstituted C2-C20 heteroarylgroup, a substituted or unsubstituted C2-C20 heteroaryloxy group, asubstituted or unsubstituted C2-C20 heteroarylalkyl group, a substitutedor unsubstituted C4-C20 carbocyclic group, a substituted orunsubstituted C4-C20 carbocyclic alkyl group, a substituted orunsubstituted C2-C20 heterocyclic group, or a substituted orunsubstituted C2-C20 heterocyclic alkyl group,

wherein, in Formula 15, R₅′ is a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, asubstituted or unsubstituted C2-C20 alkenyl group, a substituted orunsubstituted C2-C20 alkynyl group, a substituted or unsubstitutedC6-C20 aryl group, a substituted or unsubstituted C6-C20 aryloxy group,a substituted or unsubstituted C7-C20 arylalkyl group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocyclic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group; and R₆ is selectedfrom a substituted or unsubstituted C1-C20 alkylene group, a substitutedor unsubstituted C2-C20 alkenylene group, a substituted or unsubstitutedC2-C20 alkynylene group, a substituted or unsubstituted C6-C20 arylenegroup, a substituted or unsubstituted C2-C20 heteroarylene group,—C(═O)—, and —SO₂—,

wherein, in Formula 16, A, B, C, D, and E are carbon atoms; or one ortwo of A, B, C, D, and E are nitrogen atoms, and the remaining A, B, C,D, and E are carbon atoms, R₇ and R₈ are linked to each other to form aring, wherein the ring is a C6-C10 cycloalkyl group, a C3-C10 heteroarylgroup, a fused C3-C10 heteroaryl group, a C3-C10 heterocyclic group, ora fused C3-C10 heterocyclic group,

wherein, in Formula 17, A′ is a substituted or unsubstituted C1-C20heterocyclic group, a substituted or unsubstituted C4-C20 cycloalkylgroup, or a substituted or unsubstituted C1-C20 alkyl group; and R₉ toR₁₆ are each independently a hydrogen atom, C1-C20 alkyl group, a C1-C20alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, a C1-C20heteroaryl group, a C1-C20 heteroaryloxy group, a C4-C20 cycloalkylgroup, a C1-C20 heterocyclic group, a halogen atom, a cyano group, or ahydroxy group,

wherein, in Formula 18, R₁₇ and R₁₈ are each independently a C1-C20alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20aryloxy group, or a group represented by Formula 8A,

wherein, in Formulae 18 and 18a, R₁₉ and R_(19′) are each independentlya hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20aryl group, a C6-C20 aryloxy group, a halogenated C6-C20 aryl group, ahalogenated C6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20heteroaryloxy group, a halogenated C1-C20 heteroaryl group, ahalogenated C1-C20 heteroaryloxy group, a C4-C20 cycloalkyl group, ahalogenated C4-C20 cycloalkyl group, a C1-C20 heterocyclic group, or ahalogenated C1-C20 heterocyclic group,

wherein, in Formula 19, at least two groups selected from R₂₀, R₂₁, andR₂₂ are linked to each other to form a group represented by Formula 19a,the remaining R₂₀, R₂₁, and R₂₂ are each independently a hydrogen atom,a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, aC6-C20 aryloxy group, a halogenated C6-C20 aryl group, a halogenatedC6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxygroup, a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group, at least two adjacent groups selected from R₂₃, R₂₄,and R₂₅ are linked to each other to form a group represented by Formula19a, and the remaining R₂₃, R₂₄, and R₂₅ are each independently a C1-C20alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20aryloxy group, a halogenated C6-C20 aryl group, a halogenated C6-C20aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group,a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group,

wherein, in Formula 19a, R₁′ is a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, asubstituted or unsubstituted C2-C20 alkenyl group, a substituted orunsubstituted C2-C20 alkynyl group, a substituted or unsubstitutedC6-C20 aryl group, a substituted or unsubstituted C6-C20 aryloxy group,a substituted or unsubstituted C7-C20 arylalkyl group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocyclic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group, and * indicates abinding site to at least two adjacent groups of R₂₀, R₂₁, and R₂₂ inFormula 19, and a binding site to at least two adjacent groups of R₂₃,R₂₄, and R₂₅ in Formula
 19. 2. The composite of claim 1, wherein thepolymer further comprises a second repeating unit represented by Formula2, wherein the first repeating unit and the second repeating unit eachhave a mole fraction from about 0.01 to about 0.99, and a sum of themole fractions of the first repeating unit and the second repeating unitis equal to 1:

wherein, in Formula 2, A and Ar₂ are each independently a substituted orunsubstituted C6-C40 arylene group, a substituted or unsubstitutedC7-C40 arylalkylene group, a substituted or unsubstituted C6-C40 aryleneoxy group, a substituted or unsubstituted C7-C40 arylalkylene oxy group,a substituted or unsubstituted C2-C40 heteroarylene group, a substitutedor unsubstituted C3-C40 heteroarylalkylene group, a substituted orunsubstituted C2-C40 heteroarylene oxy group, a substituted orunsubstituted C2-C40 heteroarylalkylene oxy group, a substituted orunsubstituted C4-C40 carbocyclic group, a substituted or unsubstitutedC5-C40 carbocyclic alkylene group, a substituted or unsubstituted C4-C40carbocyclic oxy group, or a substituted or unsubstituted C4-C40carbocyclic alkylene oxy group.
 3. The composite of claim 1, wherein thepolymer is represented by Formula 3a, Formula 4a, or Formula 5a:

wherein, in Formula 3a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; and n, which is a degree ofpolymerization, is from about 5 to about 5,000,

wherein, in Formula 4a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; and n, which is a degree ofpolymerization, is from about 5 to about 5,000,

wherein, in Formula 5a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; and n, which is a degree ofpolymerization, is from about 5 to about 5,000.
 4. A composite membranecomprising: a polymer comprising a first repeating unit represented byFormula 1:

wherein, in Formula 1, at least one of R₁ to R₁₃ is a proton-conductinggroup, and the remaining R₁ to R₁₃ are each independently selected froma hydrogen atom, a substituted or unsubstituted C1-C40 alkyl group, asubstituted or unsubstituted C1-C40 alkoxy group, a substituted orunsubstituted C2-C40 alkenyl group, a substituted or unsubstitutedC2-C40 alkynyl group, a substituted or unsubstituted C6-C40 aryl group,a substituted or unsubstituted C7-C40 arylalkyl group, a substituted orunsubstituted C6-C40 aryloxy group, a substituted or unsubstitutedC2-C40 heteroaryl group, a substituted or unsubstituted C3-C40heteroarylalkyl group, a substituted or unsubstituted C2-C40heteroaryloxy group, a substituted or unsubstituted C4-C40 carbocyclicgroup, a substituted or unsubstituted C5-C40 carbocyclic alkyl group, asubstituted or unsubstituted C4-C40 carbocyclic oxy group, a substitutedor unsubstituted C5-C40 carbocyclic alkyloxy group, a substituted orunsubstituted C2-C40 heterocyclic group, a halogen atom, a hydroxygroup, and a cyano group, and Ar₁ is a substituted or unsubstitutedC6-C40 arylene group, a substituted or unsubstituted C7-C40 arylalkylenegroup, a substituted or unsubstituted C6-C40 arylene oxy group, asubstituted or unsubstituted C7-C40 arylalkylene oxy group, asubstituted or unsubstituted C2-C40 heteroarylene group, a substitutedor unsubstituted C3-C40 heteroarylalkylene group, a substituted orunsubstituted C2-C40 heteroarylene oxy group, a substituted orunsubstituted C2-C40 heteroarylalkylene oxy group, a substituted orunsubstituted C4-C40 carbocyclic group, a substituted or unsubstitutedC5-C40 carbocyclic alkylene group, a substituted or unsubstituted C4-C40carbocyclic oxy group, or a substituted or unsubstituted C4-C40carbocyclic alkylene oxy group; or a composite, which is apolymerization product of a composition comprising the polymer; and atleast one selected from compounds represented by Formulae 14 to 19:

wherein, in Formula 14, R₁, R₂, R₃, and R₄ are each independently ahydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, asubstituted or unsubstituted C1-C20 alkoxy group, a substituted orunsubstituted C2-C20 alkenyl group, a substituted or unsubstitutedC2-C20 alkynyl group, a substituted or unsubstituted C6-C20 aryl group,a substituted or unsubstituted C6-C20 aryloxy group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C4-C20carbocyclic group, a substituted or unsubstituted C4-C20 carbocyclic oxygroup, a substituted or unsubstituted C2-C20 heterocyclic group, ahalogen atom, a hydroxy group, or a cyano group; and R₅ is a substitutedor unsubstituted C1-C20 alkyl group, a substituted or unsubstitutedC1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenylgroup, a substituted or unsubstituted C2-C20 alkynyl group, asubstituted or unsubstituted C6-C20 aryl group, a substituted orunsubstituted C6-C20 aryloxy group, a substituted or unsubstitutedC7-C20 arylalkyl group, a substituted or unsubstituted C2-C20 heteroarylgroup, a substituted or unsubstituted C2-C20 heteroaryloxy group, asubstituted or unsubstituted C2-C20 heteroarylalkyl group, a substitutedor unsubstituted C4-C20 carbocyclic group, a substituted orunsubstituted C4-C20 carbocyclic alkyl group, a substituted orunsubstituted C2-C20 heterocyclic group, or a substituted orunsubstituted C2-C20 heterocyclic alkyl group,

wherein, in Formula 15, R₅′ is a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, asubstituted or unsubstituted C2-C20 alkenyl group, a substituted orunsubstituted C2-C20 alkynyl group, a substituted or unsubstitutedC6-C20 aryl group, a substituted or unsubstituted C6-C20 aryloxy group,a substituted or unsubstituted C7-C20 arylalkyl group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocyclic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group; and R₆ is selectedfrom a substituted or unsubstituted C1-C20 alkylene group, a substitutedor unsubstituted C2-C20 alkenylene group, a substituted or unsubstitutedC2-C20 alkynylene group, a substituted or unsubstituted C6-C20 arylenegroup, a substituted or unsubstituted C2-C20 heteroarylene group,—C(═O)—, and —SO₂—,

wherein, in Formula 16, A, B, C, D, and E are carbon atoms; or one ortwo of A, B, C, D, and E are nitrogen atoms, and the remaining A, B, C,D, and E are carbon atoms, R₇ and R₈ are linked to each other to form aring, wherein the ring is a C6-C10 cycloalkyl group, a C3-C10 heteroarylgroup, a fused C3-C10 heteroaryl group, a C3-C10 heterocyclic group, ora fused C3-C10 heterocyclic group,

wherein, in Formula 17, A′ is a substituted or unsubstituted C1-C20heterocyclic group, a substituted or unsubstituted C4-C20 cycloalkylgroup, or a substituted or unsubstituted C1-C20 alkyl group; and R₉ toR₁₆ are each independently a hydrogen atom, C1-C20 alkyl group, a C1-C20alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, a C1-C20heteroaryl group, a C1-C20 heteroaryloxy group, a C4-C20 cycloalkylgroup, a C1-C20 heterocyclic group, a halogen atom, a cyano group, or ahydroxy group,

wherein, in Formula 18, R₁₇ and R₁₈ are each independently a C1-C20alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20aryloxy group, or a group represented by Formula 8A,

wherein, in Formulae 18 and 18a, R₁₉ and R_(19′) are each independentlya hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20aryl group, a C6-C20 aryloxy group, a halogenated C6-C20 aryl group, ahalogenated C6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20heteroaryloxy group, a halogenated C1-C20 heteroaryl group, ahalogenated C1-C20 heteroaryloxy group, a C4-C20 cycloalkyl group, ahalogenated C4-C20 cycloalkyl group, a C1-C20 heterocyclic group, or ahalogenated C1-C20 heterocyclic group,

wherein, in Formula 19, at least two groups selected from R₂₀, R₂₁, andR₂₂ are linked to each other to form a group represented by Formula 19a,the remaining R₂₀, R₂₁, and R₂₂ are each independently a hydrogen atom,a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, aC6-C20 aryloxy group, a halogenated C6-C20 aryl group, a halogenatedC6-C20 aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxygroup, a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group, at least two adjacent groups selected from R₂₃, R₂₄,and R₂₅ are linked to each other to form a group represented by Formula19a, and the remaining R₂₃, R₂₄, and R₂₅ is each independently a C1-C20alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20aryloxy group, a halogenated C6-C20 aryl group, a halogenated C6-C20aryloxy group, a C1-C20 heteroaryl group, a C1-C20 heteroaryloxy group,a halogenated C1-C20 heteroaryl group, a halogenated C1-C20heteroaryloxy group, a C4-C20 carbocyclic group, a halogenated C4-C20carbocyclic group, a C1-C20 heterocyclic group, or a halogenated C1-C20heterocyclic group,

wherein, in Formula 19a, R₁′ is a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, asubstituted or unsubstituted C2-C20 alkenyl group, a substituted orunsubstituted C2-C20 alkynyl group, a substituted or unsubstitutedC6-C20 aryl group, a substituted or unsubstituted C6-C20 aryloxy group,a substituted or unsubstituted C7-C20 arylalkyl group, a substituted orunsubstituted C2-C20 heteroaryl group, a substituted or unsubstitutedC2-C20 heteroaryloxy group, a substituted or unsubstituted C2-C20heteroarylalkyl group, a substituted or unsubstituted C4-C20 carbocyclicgroup, a substituted or unsubstituted C4-C20 carbocyclic alkyl group, asubstituted or unsubstituted C2-C20 heterocyclic group, or a substitutedor unsubstituted C2-C20 heterocyclic alkyl group, and * indicates abinding site to at least two adjacent groups of R₂₀, R₂₁, and R₂₂ inFormula 19, and a binding site to at least two adjacent groups of R₂₃,R₂₄, and R₂₅ in Formula
 19. 5. The composite membrane of claim 4,wherein the polymer further comprises a second repeating unitrepresented by Formula 2, wherein the first repeating unit and thesecond repeating unit each have a mole fraction from about 0.01 to about0.99, and a sum of the mole fractions of the first repeating unit andthe second repeating unit is equal to 1,

wherein, in Formula 2, A and Ar₂ are each independently a substituted orunsubstituted C6-C40 arylene group, a substituted or unsubstitutedC7-C40 arylalkylene group, a substituted or unsubstituted C6-C40 aryleneoxy group, a substituted or unsubstituted C7-C40 arylalkylene oxy group,a substituted or unsubstituted C2-C40 heteroarylene group, a substitutedor unsubstituted C3-C40 heteroarylalkylene group, a substituted orunsubstituted C2-C40 heteroarylene oxy group, a substituted orunsubstituted C2-C40 heteroarylalkylene oxy group, a substituted orunsubstituted C4-C40 carbocyclic group, a substituted or unsubstitutedC5-C40 carbocyclic alkylene group, a substituted or unsubstituted C4-C40carbocyclic oxy group, or a substituted or unsubstituted C4-C40carbocyclic alkylene oxy group.
 6. The composite membrane of claim 4,wherein the polymer is represented by Formula 3a, Formula 4a, or Formula5a:

wherein, in Formula 3a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; and n, which is a degree ofpolymerization is from about 5 to about 5,000:

wherein, in Formula 4a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; N, which is a degree ofpolymerization, is from about 5 to about 5,000, and

wherein, in Formula 5a, X is a chemical bond, —CH₂—, —C(CF₃)₂—, —C(═O)—,—C(CCl₃)₂—, —CH(CF₃)—, —S(═O)—, —S(═O)₂—, —P(═O)C₆H₅—, or —CH(CCl₃)—;0.01≦a≦0.99; and 0.01≦b≦0.99, wherein a+b=1; and n, which is a degree ofpolymerization, is from about 5 to about 5,000.